Full Stack Developer (UK Offshore Technology)

Investec Sandton is looking for a highly skilled .NET Engineer to join our Client Digital Experience team. This team is responsible for building and maintaining externally facing APIs that power Investec's UK Open Banking ecosystem - enabling clients and partners to securely share data, initiate payments, and integrate with regulated providers across the financial industry.

You will play a key role in designing, developing, and supporting financial-grade APIs that demand the highest levels of security, reliability, and performance. This is an opportunity to contribute to a high-impact platform that underpins our client-facing digital experiences.

This role suits someone who thrives on technical excellence, accountability, and real world impact. It's a space where robust engineering meets the fast evolving world of open finance.

What you'll do

• Design, develop, and maintain secure, scalable, and high-performance REST APIs using C# and .NET Core / .NET Framework.
• Implement OAuth2 and OpenID Connect (OIDC) for secure authentication and authorization in regulated environments.
• Work closely with API gateways such as Apigee and Azure API Management (APIM) to manage, secure, and monitor external-facing APIs.
• Collaborate with product and cloud teams to ensure systems meet financial-grade security and compliance standards.
• Take ownership across the full SDLC - from design and deployment to production support and monitoring.
• Participate in a rotational standby schedule to support the stability of client-facing systems outside of normal working hours.
• Work across the stack where needed - from front-end SPAs (Angular/React) to infrastructure-as-code and CI/CD pipelines.
• Continuously drive improvement in API quality, resilience, and developer experience.

• Proven experience in building and supporting RESTful APIs using C# and .NET Core / .NET Framework.
• Strong grasp of API security principles including OAuth2, OIDC, token management, and data protection.
• Familiarity with Apigee, Azure API Management (APIM), or equivalent API gateway technologies.
• Experience with unit and integration testing, using frameworks that ensure coverage and maintainability.
• Front-end exposure to Angular, React, or similar SPA frameworks.
• Understanding of the Document Object Model (DOM) and modern UI development best practices.

• Hands on experience working with Microsoft Azure infrastructure.
• Proficiency with HTML, CSS, JavaScript, and Bootstrap.
• Familiarity with Terraform, ARM, or Bicep for infrastructure provisioning.
• Experience with document store databases (e.g. MongoDB, Cosmos DB).
• Knowledge of PowerShell scripting for automation.
• Exposure to regulated financial environments or Open Banking ecosystems.
• Awareness of how to leverage AI tools responsibly (e.g., for code generation, analysis, documentation, or testing) to enhance productivity and software quality.

• Contribute to a mission critical Open Banking platform used by real clients every day.
• Collaborate with expert engineers and product teams across South Africa and the UK.
• Be part of a culture that values excellence, creativity, and responsibility.
• Have opportunities to influence architecture, improve developer tooling, and shape our next generation of financial APIs.
• Enjoy meaningful challenges and the satisfaction of building systems that matter.

At Investec we seek creative, talented people with passion, energy and stamina, who collaborate unselfishly.